<!DOCTYPE html>
<html>
  <head>
    <meta charset="UTF-8" />
    <title>Document</title>
    <style></style>
  </head>
  <body>
    <div>
      <h1>Flow原始类型</h1>
    </div>
    <script>
      const a: string = "foo";
      const b: number = 123;
      const c: boolean = false;
      const d: null = null;
      const e: void = undefined;
      const f: symbol = Symbol;
    </script>
  </body>
</html>
